Is CVE-2021-21540 in the CISA KEV catalog?

No. CVE-2021-21540 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-21540?

CVE-2021-21540 has a CVSS v3 base score of 5.9 (MEDIUM).

What is the EPSS score for CVE-2021-21540?

CVE-2021-21540 has an EPSS score of 1.16% (63th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-21540?

Upgrade idrac9 firmware to 4.40.00.00 or later.

CVE & CISA-KEV Catalog

CVE-2021-21540

MEDIUM

5.9

CVSS v3

NVD

Description

Dell EMC iDRAC9 versions prior to 4.40.00.00 contain a stack-based overflow vulnerability. A remote authenticated attacker could potentially exploit this vulnerability to overwrite configuration information by injecting arbitrarily large payload.

CWE-121Stack-based Buffer Overflow CWE-787Out-of-bounds Write

How to fix

Remediation Available

idrac9 firmwareNVD

Affected:< 4.40.00.00Fixed in:4.40.00.00CVE-2021-21540derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityLow

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L

Exploit Intelligence

1.16%probability of exploitation in 30 days

63rdpercentile

Moderate risk: more likely to be exploited than 63% of all known CVEs.

References

Vendor Advisory1

dell.com

Related Vulnerabilities

Other CWE-121 (Stack-based Buffer Overflow) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2025-22457	Critical	9.0	100%	KEV + Ransom	Fix
CVE-2025-0282	Critical	9.0	100%	KEV + Ransom	-
CVE-2021-20038	Critical	9.8	100%	KEV + Ransom	-
CVE-2009-0927	High	8.8	97%	KEV	Fix
CVE-2020-10924	High	8.8	87%	-	-
CVE-2022-20705	Critical	10.0	80%	-	-

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.